Improper 30-amp pedestal design is dangerous

If you can’t plug in fully, you’re just asking for a melted shore power plug!

Dear Mike,

At a few campgrounds the design of the electric pedestal and my power plug prevented my 30 amp plug being fully inserted into the receptacle. A metal lip just below the 30 amp receptacle stuck out too far and I could not fully engage the plug into the receptacle.

Ledge on bottom won’t allow plug to fully seat

Even though the 30 amp receptacle was in good condition, I was forced to use my 50amp/30 amp dogbone. With all the reports of melted 30-amp plugs lately, I am very hesitant to use a receptacle which my plug cannot engage 100%. - an RVelectricity reader

Dear RVe Reader,

One of your options is to use a 50/30-amp dogbone adapter like this one. As I discussed in a previous blog, a properly wired 50/30-amp adapter only uses one pole of the 2-pole 50-amp outlet, so if supplies the correct 120 volts to your 30-amp RV. But is this really safe?

But is it safe to plug a 30-amp cord into a 50-amp breaker?

While this works, it’s technically a code violation since a 10-gauge, 30-amp shore power cord isn’t protected from a possible 50-amperes of over-current. But as long as your RV’s 30-amp main breaker is operating properly, this should be safe. I really don’t like it, but dozens of manufacturers make and sell these 50/30-amp adapters. However, there’s an extra safety feature you can add yourself.

The Hughes PowerWatchdog Solution!

Interestingly, the 30-amp Hughes Power Watchdog surge protector includes a 30-amp over-current trip function. So if you plug one into a 50-amp pedestal outlet using a 50/30-amp dogbone adapter, then plug your RV 30-amp shore power cord into the Power Watchdog, you’ve essentially added a 30-amp breaker at the 50-amp pedestal outlet. This should be 100% safe under nearly all possible failure modes, with the rare exceptions of an RPBG mis-wired outlet, or a Reflected Hot-Skin voltage. But more on those conditions later.

Let’s play safe out there - Mike